A gunman in the botched Chelsea robbery that left rapper Freaky Zeeky shot in the gut and his friend dying smirked throughout his sentencing yesterday – even as he heard of the agony he’d caused a 3-year-old girl.

“I tell her he’s in heaven,” the mother of victim Eric Mangrum, 28, said of Mangrum’s little daughter, Nyah.

Convicted murderer Chauncey Dillon, 29, of Brooklyn, continued to smirk, even as Rosen went on to read aloud about how Nyah refused to leave her Bronx home this past Father’s Day – thinking the holiday meant her father was coming home.

The smile only faded from Dillon’s face when Manhattan Supreme Court Justice Bonnie Wittner sentenced him to 30 years to life in prison – meaning he’ll be 59 before a parole board will even consider freeing him.

Dillon was a parolee with a record for two armed robberies and a drug deal when he pulled his gun and joined with two friends in trying to grab a flamboyant gold and diamond-encrusted medallion from Freaky Zeeky’s neck. The robbery occurred after a fender-bender at 22nd Street and Sixth Avenue in April 2003.

Freaky Zeeky, real name Ezekial Jiles – a member of the Diplomat rap group and owner of his own 11-page rap sheet – testified against Dillon.

In order to come to court, the rapper needed a day off from Rikers Island, where’s he’s completing a 35-month sentence for ecstasy possession.

On the witness stand, Freaky Zeeky was unable to remember much more than that the man who shot him, gun-butted him twice, and threw him into a pile of curbside garbage was wearing green.

But prosecutors were able to show jurors a surveillance video that showed Dillon throwing Freaky Zeeky into the trash bags while wearing a green jacket.

Dillon’s lawyer, James McQueeney, tried unsuccessfully to convince the judge that 15 years to life, the minimum allowable, would be adequate. Dillon wasn’t the shooter, and didn’t even have a gun, the lawyer insisted.

But the judge insisted, “This is a dreadful, horrible crime aggravated by the fact that this was on a residential street.”